The invention relates to a method for controlling adjustment drives of a motor vehicle seat for longitudinal and tilting movement of the seat and, more particularly, to a vehicle seat positioning control method utilizing positioning switching elements and a switching device corresponding with the seat back to block an associated adjustment device before the seat back runs into an obstacle in its adjustment range.
A device for carrying out a method for controlling a vehicle seat is already disclosed in DE-OS 3,137,150. A blocking logic is provided in the control of at least two adjustment devices for adjustment of the inclination of the seat back and the longitudinal position of the seat. In the case of simultaneous movements of the two adjustment devices for the purpose of adjusting the motor vehicle seat into the recumbent position or out of the recumbent position, the logic prevents it from being jammed. This is accomplished by virtue of the fact that, when the inclination of the seat back falls below a specified value, the adjustment devices approach their position in succession. Irrespective of the fact that successive activation of the adjustment devices is only possible for the inclination of the seat back at the predetermined angle, this method, on one hand, entails long adjustment times and, on the other hand, the range of adjustment of the seat back is considerably restricted.
It is an object of the present invention to provide a controlling method of the aforementioned type which permits an optimum sequence of motions when there is an obstacle within the range of adjustment of the seat back.
This object is achieved using a method in which, among other things, with rearward tilting movement of the seat back initiated by a positioning element and shortly before the seat back runs into the obstacle with the blocking of the adjustment device for a further tilting movement of the seat back, a longitudinal movement of the seat forward is automatically initiated by a switching device again and, in addition to the longitudinal movement of the seat, rearward tilting movement is also continued again either until the next time blocking occurs or until the set lowered position of the seat back is reached.